Creatine is in no way going to make or break your fitness. Lifting heavy, eating enough calories and protein (which usually includes taking whey), and sleeping enough take you 95% of the way, yet supplements for that 5% difference usually account for 95% of the consideration and discussion in the fitness community instead of 5%. It's a silly trap to fall into.
As far as those secondary supplements go, though, creatine is the most proven and significant of the bunch for helping your lifts, and fish oil is the most proven and significant for general health benefits (cardiovascular health, assisting in shedding fat when coupled with cardio, even psychological health).
So if you're concerned with that sort of stuff, drop the 5g of creatine into your blender with your protein shake and don't concern yourself with anything else. I tell everyone to take fish oil though. Omega-3:Omega-6 ratios are super important for your health, and unless you're eating free-range everything you're likely barely getting any in your diet.
I know creatine isn't some magical steroid or mass gainer, I'm just curious as to when to expect to see that small increase in weight or reps at the gym, or the slightly bigger muscles due to the water retention. As far as I'm concerned, allowing you to do a couple extra reps could be chalked up to having a "good day" at the gym. Sometimes I do do an extra couple reps for an exercise than I usually do, so I'm not sure where sleeping well/eating well ends and the creatine "help" starts to take over, know what I'm saying?
I took fish oil (orange flavoured, yuck) a little while ago but never re-upped when I finished the bottle. S'pose you could also just drop a tablespoon of that along with creatine into your protein shake?